… profit margins A method to make hollowcore slabs fixed at their ends which allows for a reduction of up to 20% of the depth and consumption of concrete of finished floors has been developed, thoroughly tested and protected by patents by the engineering company Elastic Potential, in Barcelona, Spain. The method consists of producing hollowcore units with deep grooves across their top surface. Once at the job site, right on top of the grooved slabs one places negativemoment resistant reinforcement bars and pours a conventional topping, 50 mm thick at least. The significant cost reductions in the production and transportation of slabs allow the precaster to rapidly amortize the new machinery required to produce the grooved slabs. At the present date, leading machinery suppliers already have machinery available to produce Grooved Hollowcore slabs or are developing it and plan to have it soon available (Prensoland, Echo Precast Engineering, UltraSpan, Elematic, Nordimpianti, Spancrete).